Not yet - but I'm thinking about it. :) We don't do many voice calls, though, so I haven't felt a strong enough need. Mostly we use IM/Email since that is less disruptive while working and more conducive to our mobile lifestyles. (Not all of us work from home, there's a small core group of friends who started the company that work together in an office in person, but they do so by choice and it sounds pretty fun. Sorta wish I could drop in now and then without having to board a plane to do it.)